Phys.org September 30, 2020 Oceanic animals and their predators employ a cross-wavelength detection strategy. Inspired by these animals an international team of researchers (China, USA – UC Berkeley, Lawrence Berkeley National Laboratory, Duke University) proposed a new concept of cross-wavelength invisibility that integrated a variety of invisibility tactics. They presented a Boolean metamaterial design strategy to balance divergent material requirements across cross-scale wavelengths. As a proof of concept, they simultaneously demonstrated longwave cloaking and shortwave transparency using a nanoimprinting technique. The work extended stealth techniques from individual strategies of invisibility targeting a single-wavelength spectrum to integrated invisibility targeting cross-wavelength applications. […]
Tag Archives: Biomimetics
Researchers create fly-catching robots
TechXplore September 28, 2020 An international team of researchers (Austria, Germany) has created a soft robot and demonstrated a series of simulation-guided lightweight, durable, untethered, small-scale soft-bodied robots that perform large-degree deformations at high frequencies up to 100 Hz. They are driven at very low magnetic fields down to 0.5 mT and exhibit a specific energy density of 10.8 kJ m−3 mT−1. They observed asynchronous strongly nonlinear cross-clapping behavior of the robots in experiments and analyzed by simulation, breaking ground for future designs of soft-bodied robots. The robots walk, swim, levitate, transport cargo, squeeze into a vessel smaller than their dimensions and can […]
Anti-reflective nanocoating inspired by fly eyes
Nanowerk September 16, 2020 Insect eyes have an anti-reflective coating which has been shown to provide anti-adhesive functionality. Researchers in Switzerland demonstrated a clear link between the morphology and function of the nanocoatings on Drosophila corneas. They found that nanocoatings that consist of individual protrusions have better anti-reflective properties, whereas partially merged structures have better anti-adhesion properties. Using biochemical analysis and genetic modification techniques they reverse engineered the protein Retinin and corneal waxes as the building blocks of the nanostructures and established low-cost production of Retinin. Mixing this synthetic protein with waxes they forward engineered various artificial nanocoatings with insect-like […]
Swarming locusts inspire new collision detector
Physics World September 7, 2020 Collision avoidance models based on image processing algorithms have been implemented using analogue very-large-scale-integration designs, but none is as efficient as this neuron in terms of energy consumption or size. The lobula giant movement detector (LGMD) neuron in locusts can detect an approaching object and prevent collisions within a swarm of millions of locusts. This single neuronal cell performs nonlinear mathematical operations on visual stimuli to elicit an escape response with minimal energy expenditure. An international team of researchers (USA – Pennsylvania State University, India) developed a nanoscale collision detector that mimics the escape response […]
Moth-eye nanostructures make good anti-icing coatings
Physics World September 3, 2020 Researchers in Vietnam fabricated moth eye structure on the quartz substrate covered with a flat paraffin layer to isolate it in a cold and humid environment. The paraffin layer only stayed on the top of the nanostructure, separated it from the outside environment to obstruct heat energy being transferred to the cold substrate, and prevented the wetting transition, which was observed regularly on the rough surface. Numerous air blocks trapped inside the nanostructure also contributed to delayed heat transfer, leading to an increase in the freezing time of the attached water droplet. The nanostructure coated […]
Self-healing soft material outsmarts nature
Nanowerk July 27, 2020 Current self-healing materials have shortcomings such as low healing strength and long healing times limit their practical application. An international team of researchers (USA – State University of Pennsylvania, Germany, Turkey) studied the molecular structure and amino acid sequences of squid proteins and developed a new stretchable biosynthetic material using protein engineering. The squid takes longer to heal because the molecular structure of the proteins inside its tentacles is not perfectly intertwined. With the laboratory-developed squid-inspired material, the scientists changed the nanostructure of the molecules until they created crosslinks between all of them in such a […]
Shells and grapefruits inspire first manufactured non-cuttable material
Science Daily July 20, 2020 An international team of researchers (UK, Germany) has created a bio-inspired metallic cellular structure (with an internal grid of large ceramic segments). It is non-cuttable by an angle grinder and a power drill, and it has only 15% steel density. The architecture derives its extreme hardness from the local resonance between the embedded ceramics in a flexible cellular matrix and the attacking tool, which produces high-frequency vibrations at the interface. The contrast between the ceramic segments and cellular material was also effective against a waterjet cutter because the convex geometry of the ceramic spheres. Shifting […]
Liquid crystals create easy-to-read, color-changing sensors
Nanowerk July 11, 2020 Inspired by the ability of chameleons to change color by using temperature to direct the skin tissue that contains nanocrystals reflecting light, to expand or contract, an international team of researchers (USA – University of Chicago, University of South Carolina, University of North Texas, Cornell University, Argonne National Laboratory, Mexico, Turkey, Colombia) has developed a way to stretch and strain liquid crystals to generate different colors. They dispersed chiral droplets in polymer films and deformed it by inducing uniaxial or biaxial stretching. Their measurements are interpreted by resorting to simulations of the corresponding systems, thereby providing […]
Highly sensitive sensors show promise in enhancing human touch
Nanowerk February 18, 2020 People rely on a highly tuned sense of touch to manipulate objects, but injuries to the skin and the simple act of wearing gloves can impair this ability. Researchers in China have developed a visually aided tactile enhancement system for precise motion control by combining ultrathin, highly sensitive, crack-based strain sensors and signal acquisition circuit with real-time display equipment. With the optimization of the thicknesses of the substrates and sensitive films of the strain sensors, the device has a detection limit as low as 0.01% and an ultrahigh gauge factor of 44 013 at a strain of […]
This humidity digester breathes in atmospheric water and exhales energy
Science Daily November 20, 2019 Researchers in Singapore have developed a humidity digester composed of a moisture hydrogel based zinc and cobalt, cathode, photoanode, and a solar cell. Just like batteries, it generates power from atmospheric humidity instead of an electrolyte. The photoanodes, acting as a photo-electrocatalyst, oxidize the absorbed water in the presence of light to split water and produce energy. The hydrogel constantly replenishes the system with water that is pulled out from the air to sustain the energy generation process. The assembly generates electricity while dehumidifying the room. The second-generation cobalt hydrogel absorbs moisture faster than any […]